Such an apparatus typically has a fiber supply with at least one fiber-supply conduit to which air is fed to transport the fibers, the conduit being connected, e.g. through a curved fiber diversion conduit to a fiber-discharge conduit, a chute downstream of the fiber-discharge conduit, a glue applicator between the fiber-discharge conduit and the chute and having spray nozzles for coating fibers emerging from the fiber-discharge conduit and entering the chute with glue droplets, and a collection device with a conveyor downstream of the chute for catching and optionally removing the fibers, and a suction device for drawing air from the chute through the conveyor belt. The conveyor is preferably designed as an air-permeable conveyor belt, e.g. a screen belt, wherein the suction device is below the conveyor belt. Furthermore, an air-jacket forming device with one or more air-jacket lines to generate an air-jacket stream surrounding the fiber flow in the chute is preferably provided below the glue applicator, and thus in the upper region of the chute. Both the transport air and the jacket air are aspirated through the air-permeable conveyor belt by means of the suction device. What is thus effected is that the fibers are fed pneumatically, the fibers entering the region of the glue applicator from the fiber-discharge conduit that is typically vertical. That is where the spray nozzles are used to apply glue droplets to the fibers. The fibers then drop through the chute onto the conveyor belt that is below the chute. The glue-coated fibers come to rest on this conveyor belt.
Any unused glue falling within the chute passes onto the fibers on the conveyor belt, thereby ensuring complete utilization of the glue and reliably preventing contamination of the apparatus by unused glue. MDF board refers to medium density fiberboard.
Apparatuses for applying glue to fibers for the fabrication of fiberboard of the type described in the introduction have been disclosed, for example, in DE 102 47 412, [WO 2004/035279], DE 102 47 413 [WO 2004/035278], DE 102 47 414 [WO 2004/052603], and DE 10 2004 001 527 [WO 2005/065905]. In the known apparatuses, the spray nozzles are on at least one nozzle ring surrounding the fiber stream emerging from the fiber-discharge conduit, or they form a nozzle ring surrounding the fiber stream. The adjustment angle of the spray nozzles relative to the fiber stream and/or the distance of the spray nozzles from the fiber stream is adjustable. In addition, the spray nozzles can be made changeable in their position, e.g. in a movable fashion on the nozzle ring. The known apparatus thus allows for adjustment of the spray nozzle position to meet requirements. The known measures have proven to be successful in principle, however, they are capable of being further developed.